Fig. 4. Gfi1 and Math1 expression in hair cells of Math1 and Gfi1 mutants. (A-F) Gfi1 expression in wild-type and Math1 mutant mice. (G-J) Math1/ß-Gal expression in Gfi1 mice. (A,C,E,G,I) Wild-type littermates (+/+). (B,D,F) Math1 null mutants (-/-). (H,J) Gfi1-null mutants (-/-). (A,B) Gfi1 mRNA expression in both wild-type and Math1 null otic vesicle (OV) at E12.5. (C,D) Gfi1 protein expression in wild-type but not Math1 null otic vesicle (OV) at E12.5. Arrow indicates position of Gfi1-positive cells (E,F) Loss of Gfi1 mRNA expression at E18.5 in the Math1 null mutant utricle (U), saccule (S) and cochlea (Co), presumably due to loss of hair cells. (G-J) Math1/ß-Gal expression (blue) and hair cell placement are visualized by the ß-galactosidase cassette driven by the Math1 promoter in P0 coronal sections of the ear. Sections are counterstained with Nuclear Fast Red (pink). Some of the stereocilli are visible (small arrows). (G) Gfi1 wild-type saccule showing a single layer of blue stained hair cells and a single layer of pink stained support cells. (H) Gfi1-null saccule showing the disorganization of the hair cell `layer'. Note that some hair cells are placed completely beneath others in the layer (large arrows) (see Fig. 3A-D for comparison). (I) Gfi1 wild-type cristae showing normal development of hair cells and expression of Math1. (J) Gfi1-null cristae showing normal development of hair cells and expression of Math1.

Return to article